Extract from article by Michael Mainelli
Cryptocurrencies such as Bitcoin have increased the awareness of distributed ledgers with their use of a particular type of ledger — blockchain — to hold the details of coin accounts among millions of users. Cryptocurrencies have certainly had their own problems with their wallets and exchanges — even ID-kaarts are not without their technical problems — but the distributed ledger technology holds firm for Estonia and for cryptocurrencies. These technologies have been working in hostile environments now for nearly a decade.
The problem with a central database like the ones used to house social security numbers, or credit reports, is that once it’s compromised, a thief has the ability to copy all of the information stored there. Hence the huge numbers of people that can be affected — more than 140 million people in the Equifax breach, and more than 50 million at Home Depot — though perhaps Yahoo takes the cake with more than three billion alleged customer accounts hacked. Of course, if you can find a distributed ledger online, you can copy it, too. However, a distributed ledger, while available to everyone, may be unreadable if its contents are encrypted. Bitcoin’s blockchain is readable to all, though you can encrypt things in comments. Most distributed ledgers outside cryptocurrencies are encrypted in whole or in part. The effect is that while you can have a copy of the database, you can’t actually read it.